PS 89 principal Ronnie Najjar has stepped down from the position she has held since the school opened in 1998, ending a nearly three-decade run at one of the neighborhood’s four elementary schools. It’s a huge loss for the school, which has thrived under her leadership. Ask any parent or kid over these 30 years — she has been a guiding force.

PS 89, aka the Liberty School, opened on September 10, 1998 — a year after the 25-story building at 201 Warren was built. Just a few years before that, Stuyvesant High School, built in 1992, was the only thing in that northern parcel. The school, five stories in the base of the building, was built on Battery Park City Authority land leased to the city for $1 a year.

At that time, Ronnie was teaching at PS 234 — she had been there for a decade — and was picked to be the first principal of the fledgling school across West Street. She had her master’s degree in administration, but she kept that in her back pocket.

“I loved being in the classroom, why would I ever leave?” she said in between visits from students one morning this week. “But I thought I would try it for a year. And then there’s always more to do — always more to learn. I just kept on keeping on.”

Ronnie, a Brooklyn girl who grew up in Park Slope, taught at Brooklyn Friends right out of college, and then came to PS 234 in 1988, when it moved to its new building on Greenwich and Chambers. (PS 234 opened in the former PS 150 space in Independence Plaza in 1976 as an annex to PS 130, then later as an annex to PS 3.) She taught grades two through five, which probably gave her edge as a principal.

The school started with 98 students and 12 staff members across grades pre-K through three. They added a grade a year from there.

She called the idea of starting a new school “terrifying,” but looking back, “I’d rather start a school than inherit one. All the successes were mine, and all the challenges were mine. I had to own it.”

And did just that in two citywide crises: Ronnie saw the school through two terrorist attacks — September 11, 2001, and the Halloween rampage in 2017. After that second event, The Times did a feature in on that horrible coincidence. In 2001, Ronnie had been standing in the schoolyard when the first plane hit the North Tower.

“I snapped into crisis mode,” she told The Times. “She gathered students and teachers and led them a mile away to P.S. 3 in the West Village. ‘It was terrifying, but I was really calm.'” The school was closed for five months, reopening on March 1, 2002, with balloons, banners and cheerleaders from Stuy.

That was year four. Ronnie would go on to launch one of the city’s first ICT classes — integrated co-teaching — and raise the school’s ranking up to one of the best in the city. That’s a point of pride for her: that the school is committed to heterogeneous classes and committed to serving diverse group of learners. And that the school has been able to maintain its art programming, even in lean budget years.

Replacing her as of August is the current assistant principal, Thao Vo.

Ronnie is not sure what she will do next — she is still too mentally and emotionally engaged with this job — but she said she leaves knowing the school’s foundation is firmly in place thanks to her staff, the parents and of course, she said, the kids.

“I feel like we all built a school that is an anchor in the community,” she said. “I know everyone will keep the vision alive.”